There is a technique of transmitting a power between a crankshaft and accessories by a driving belt wound around an engine crank pulley and accessory pulleys. For example, Patent Document 1 discloses such a technique of transmitting a power between a crankshaft and accessories by a driving belt wound around accessory pulleys and a crank pulley.
In Patent Document 1, mount brackets for fixing an engine to a vehicle body are bolted and fixed to an engine body via attaching portions in such a manner that mount brackets straddle on both sides of a cylinder head and a cylinder block.
Also, in the engine disclosed in Patent Document 1, a belt tensioner is disclosed in which one end of a spring damper unit is swingably fixed to a crank case via a shaft, the center of an arm portion is swingably fixed to an AC generator support portion of a cylinder block via a pivot portion, the other end of the spring damper unit and one end of the arm portion are pivotally connected to each other via a shaft, and also the other end of the arm portion is rotatably supported by a shaft. Also, due to a stretching force by a spring of the spring damper unit, the tensioner pulley is always pressed against a belt via the arm portion.
Patent Document 1: Japanese Patent Application Publication No. H08-100670A
In the engine disclosed in Patent Document 1, the one end of the spring damper unit is arranged outside a front cover. Namely, because the spring damper unit protrudes outward in a width direction of the front cover, a dimension of the engine in the width direction is increased and thus an engine mount space is also increased.